Diodes Incorporated AP131-29WG-7

Overview

AP131-29WG-7 from Diodes Incorporated is a 300mA fixed-output low-dropout linear regulator with 2.9V output, 400mV dropout at full load, ±2% output accuracy, 50µA quiescent current, and active-low enable control. It integrates current limiting, thermal shutdown, and bandgap reference, and is used in battery-powered wireless modules requiring stable low-noise voltage regulation.

For engineers reviewing the AP131-29WG-7 datasheet, AP131-29WG-7 pinout, AP131-29WG-7 application, or AP131-29WG-7 equivalent, key selection criteria include dropout voltage under 300mA load, EN pin logic polarity, BP pin noise-filtering capability, SOT25 thermal resistance (163°C/W), and RoHS/Green compliance status.

Technical Context

The AP131-29WG-7 employs a PMOS pass transistor with 1.5Ω on-resistance, enabling low dropout and zero base current draw. Its error amplifier compares feedback from an internal 1.08V bandgap reference to regulate output precisely across line and load variations.

Enable control is active-low: the device powers up only when EN is pulled high (≥1.5V), and enters ultra-low standby mode (<5µA) when EN is low. The BP pin accepts an external 0.1µF capacitor to reduce output noise via bandgap bypass.

Key Specifications

Pinout & Package

SOT25 package: 5-pin surface-mount, 2.8mm × 2.9mm footprint, 1.1mm height, lead-free and halogen-free "Green" molding compound.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO regulator applications.

Compared with AP7343-29W-7 and MCP1700T-2902E/TT, the AP131-29WG-7 balances moderate IQ, proven thermal robustness in SOT25, and BP-enabled noise control-making it optimal for cost-sensitive industrial and consumer wireless designs where 300mA capability and active-low enable are essential.

Availability

AP131-29WG-7 is available at Aetrix Electronics and suitable for battery-powered devices, wireless communication modules, and PC peripheral power management requiring stable component supply and RoHS-compliant sourcing.

Supply support for AP131-29WG-7 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in power management, signal integrity, and protection solutions for industrial, computing, and consumer markets.

The AP131 series targets cost-effective, low-power LDO applications in space-constrained portable electronics, emphasizing dropout performance, quiescent current, and integrated protection features.

FAQ

What is the minimum input voltage required for AP131-29WG-7 to maintain regulation at 300mA?

The minimum input voltage is 3.3V: with 2.9V nominal output and 400mV typical dropout at 300mA, VIN must be ≥ VOUT + VDROP = 3.3V. Operation below this causes output collapse, confirmed by DS31046 Rev. 8 Figure 4 (Dropout vs. Load).

Can the BP pin be left unconnected?

Yes, the BP pin may be left floating or tied directly to GND, but doing so forfeits the 0.1µF bypass benefit. Without the capacitor, PSRR degrades by ~15dB at 100Hz and output noise increases measurably, per DS31046 Figure 1 and Typical Characteristics section.

Is AP131-29WG-7 pin-compatible with other AP131 variants?

Yes-all AP131 variants (e.g., -15W, -33W) share identical SOT25 pinout and electrical behavior except output voltage. The EN, BP, IN, OUT, and GND terminals map identically; only the internal resistor divider changes to set VOUT.

Does AP131-29WG-7 require an output capacitor for stability?

Yes, a minimum 10µF ceramic output capacitor is required for stability across all loads, as specified in DS31046 Section "Typical Applications Circuit" and Absolute Maximum Ratings. Using less than 10µF risks oscillation, especially under light load conditions.